How to Grout a Kitchen Backsplash: Step-by-Step Guide for Beginners
- Isaac Ostrom
- 5 days ago
- 11 min read
Grouting a backsplash feels intimidating for a lot of people. I get it. You spend all this time setting tile, getting your layout right, making your cuts, and then grout feels like the moment where you can ruin everything in about 10 minutes if you do it wrong.
But here’s the truth. Grouting is pretty simple when you have the right grout, the right tools, and you understand the timing. Timing is the whole game. Especially when you’re working with a faster setting grout.
In this post I’m walking you through exactly how I grout an irregular subway tile backsplash step by step, including how I mix it, how I spread it, how I wipe it, how I keep my joints looking clean, and how I avoid the most common callback in the whole backsplash world: that bottom joint cracking where the countertop meets the wall.
If you’re a beginner, I’m going to keep this friendly. If you’re a pro, there are still a couple little moves in here that will make your cleanup faster and your finished joints cleaner.
Key Takeaways for Homeowners and Pros [TLDR Version]
If your grout joints vary between 1/16 and 1/8 inch, Custom Prism is a solid option and easy to find. I’m using bright white.
If you’re a beginner, white grout with white tile is your best friend. It hides little goof ups and blends nicely.
Put water in the bucket first, then add powder, and protect your lungs. Don’t breathe grout dust.
Mix to a consistency that can move into the joints but is not so runny it turns into a mess.
Let the grout slack for 5 minutes, then remix. That slake time matters.
When spreading, use a shallow angle around 20 to 22 degrees to pack joints, and a sharper angle around 45 degrees to pull more off the face.
The bottom joint where tile meets countertop is a common crack spot. If you’re worried about callbacks, consider a color matched sanded caulk there.
Prism is rapid setting. Work in smaller sections so it doesn’t set up on you.
First wipe is for shaping joints with as little water as possible. Circular motion helps smooth things out.
Wait about 10 minutes and do a final wipe to remove haze, then later buff with microfiber towels. You can even buff the next day.
Tools Required
Here’s what I’m actually using in the process:
Grout
Custom Prism grout (bright white in my case)
Mixing and safety
Bucket
Water
Margin trowel (also used for tight spots and corners)
Respirator or mask (grout dust is no joke)
Gloves (cement products will wreck your hands)
Spreading and wiping
Grout float
Sponge
Second bucket for clean water
Microfiber towels for the final buff
Optional blue tape to protect a painted wall edge
Step 1: Pick the Right Grout Color (Especially If You’re New)
Let’s start with grout choice and color, because this is where beginners make their life harder than it needs to be.
My joints on this backsplash are varying between 1/16 and 1/8 inch. That’s super common with handmade or irregular subway tile because the tile has undulations and you’re not dealing with perfect factory edges. For that joint range, I’m using Custom Prism. You can grab it at Home Depot and it’s a good grout.
Color wise, I’m using bright white.
And I’ll tell you exactly why. If you’re a beginner, white grout with white tile is the best bet because it hides imperfections and blends your minor goof ups. You still see the tile because the tile has texture and movement, but the grout isn’t screaming at you.
Could you do a light gray or gray? Sure. But understand what you’re doing. Gray grout makes every individual tile pop out, and it makes every imperfection pop out too. So if you’re learning, go easy on yourself. White on white is a confidence builder.
Step 2: Mix the Grout the Way the Bag Says, But Here’s My Real World Method
Mixing grout is one of those things where people either overthink it or they wing it so hard they end up with soup.
First thing I do is add water to the bucket first. I’m not mixing a whole bag for a backsplash, so I’m just using what I need, but the method stays the same. Water first, powder second.
Now, safety. Wear a respirator or at least a mask. You do not want to breathe grout dust all day. When I’m mixing, I’m mindful of where I stand so I’m not in the cloud. I’ve been doing this a while, so I know how to stay out of it, but that dust is still no joke.
What consistency am I aiming for?
I want it to move into the joints, but I don’t want it so runny that it turns messy. Not stiff, not soup. If you’ve done it a bunch, you learn what that looks like, but if you’re new, follow the bag ratios and then adjust slightly from there.
Let it slack, then remix
After mixing, let it slack for 5 minutes, then remix. This matters. Slacking gives it a little initial set and then when you remix, it loosens back up and it’s ready to use.
If you skip that step, you’re fighting the grout the whole time.
Step 3: Set Up Your Tools (You Don’t Need a Garage Full of Stuff)
For a backsplash grout job, I keep it simple:
Grout float
Sponge and water bucket
Margin trowel
Microfiber towels for later
That’s it. That’s the whole deal.
Microfiber towels are one of those things you don’t realize you need until you use them once, then you never go back. They make that final cleanup and buff so much easier.
Step 4: Protect What Needs Protecting (But Don’t Panic)
People always ask about the countertop. Do I need to cover it?
If you’re working over granite or quartz, I’m not super worried about it. You can plop grout right on the countertop and keep moving. If it was marble, yeah, I’d protect it. Marble can be more sensitive and you don’t want to risk staining or scratching during cleanup.
If you’re working near a painted wall edge or you’re worried about making a mess, throw up some blue tape. Especially on that outside edge where tile meets wall. It just saves headaches.
Step 5: Pack the Joints (This Is Where Technique Matters)
Now we’re spreading grout.
Here’s what I’m doing with my float:
I pack grout into the joints at a shallow angle, around 20 to 22 degrees.
Then when I want to pull more grout off the face, I hold the float more like a 45 degree angle.
You can do both directions. Backhand, forehand. You’ll get the feel. And yes, I make it look easy because I’ve done it a lot, but it’s not complicated. The goal is simply to smash grout into the joints and then get as much off the tile face as you can.
Work clean to make cleanup easy
The more grout you remove with the float up front, the easier wiping is later. Use the float to scrape down the tile faces as you go. You’re basically helping your future self.
Tight spots and cabinets
Cabinets can be tricky because the float doesn’t always fit cleanly. That’s where the margin trowel comes in. Use it to push grout into tight spots and clean up areas the float can’t reach.
Also, most grout floats have two ends. One is more squared off and sharp, and the other is rounded. The rounded end is really nice for your initial wipe in corners because it leaves a little more grout. Then you can come back and sharpen things up with the squared edge.
Step 6: The Bottom Joint (Countertop to Wall) and Why It Cracks
Let’s talk about the crack joint, because if you ever get a backsplash callback, it’s usually here.
That bottom joint where the backsplash meets the countertop is a transition. If there’s movement, grout does not like movement. It can crack. I’ll usually grout it first because I think grout looks better, and a lot of times it doesn’t crack. But if I get a callback, we’ll come back and use a color matched sanded caulking.
If you’re really worried about callbacks, you can just preemptively use that sanded caulking there from the start. It depends on the house and how much movement you’re dealing with, and also how well the countertop is secured. If someone steps or jumps on a countertop that isn’t anchored well, you can get separation right there.
If you want a rough real world stat from my experience, it’s not every job. It’s maybe one in ten or one in fifteen backsplashes where we get a call back for that bottom joint cracking.
So no, you don’t need to panic. You just need to know it’s a thing.
Step 7: Work in Small Sections (Because Prism Sets Fast)
Custom Prism is rapid setting. That means it sets up fast. If you mix a bunch and try to grout your whole kitchen in one shot, you’re going to get cooked.
If you’re a beginner, do smaller sections. There’s no harm in that. Do a section, get the feel, wipe it, then move on.
Also, the tile itself matters here. This install is pretty beginner friendly because the tile has a glossy glaze. Grout doesn’t stick to a glossy surface like it does on a rough matte tile with nooks and crannies. So if you’re learning, this is a good style of backsplash to start with.
Step 8: When Do You Start Wiping? Use the Finger Test
This is the biggest question people ask: how long do I wait before wiping?
I don’t set a timer and walk away. I use the grout and the tile to tell me when it’s time.
In the video, I’m working with bisque ceramic and you can literally see how porous it is. It sucks water out of the grout, which helps it start setting faster, but the tile surface is glazed so the grout isn’t drying onto the face the same way it would on a porous matte tile.
Here’s the test. Touch the grout with your finger. If you can’t push it in anymore, it’s ready to wipe.
And do not over spread a huge area before you wipe. Because once it sets up too far, there’s no going back. You can ruin your whole job. Stay on it.
Step 9: First Wipe Is for Shaping, Not Perfection
My first wipe is not me trying to make it perfect. My first wipe is shaping joints.
I wring the sponge out as much as possible. I don’t want a bunch of water. Too much water is how you wash joints out, weaken grout, and make your joints look inconsistent.
I use a circular motion to even out and smooth the joints. That helps bring out a nice consistent sanded texture.
And I’m not stressing if I see little voids. I’m not tripping on that because I’m going to come back and touch them up. Same with corners. Don’t try to get corners perfect on the first pass. Get them close, then fix them later.
Also, a practical note: customers might stress seeing grout all over their countertop. Even if quartz doesn’t absorb it and it’s fine, it can still freak people out. So if you’re working in someone’s house, covering the countertop can help them relax.
Step 10: Wait About 10 Minutes, Then Do the Final Wipe
After the first wipe, I let it set up for about 10 minutes and then I do another wipe. You have a little more wiggle room between first wipe and second wipe than you do between spreading and first wipe. The grout is starting to set more now, which is good, because you can remove haze without wiping grout out of joints.
When I do the final wipe:
I go one pass with each side of the sponge.
I’m often wiping on a 45 degree angle to the joints.
I’m mainly removing haze, that film on the surface.
This is also when I’m inspecting joints for pinholes or little voids. And this is why I always keep a little grout left over after spreading, so I can do touch ups while I’m in the cleanup stage.
Fresh water matters
Swap your water. Use fresh water when you’re doing clean wipes. Dirty water just smears haze around.
Step 11: Corners and Details: Margin Trowel and Gloves
When grout starts setting up, you can shape it and work it a little more cleanly. That’s when I like using a nice sharp margin trowel to tighten up corners and make them look crisp.
And wear gloves. Seriously. Cement products will wreck your skin, and some people are more sensitive to it than others. If you’re a beginner, wear gloves even while spreading. Protect your hands.
Step 12: Final Buff and Cleanup (This Is Where It Starts Looking Expensive)
Once your joints are shaped and you’ve done your final wipe, you’re basically done with the stressful part.
Now it’s just cleanup and polish.
You can come back in a couple hours, or even the next day, and do a final buff. There’s no real rush on this part.
This is where microfiber towels shine. Wipe cabinets down, get all haze off, and buff the tile. That final buff removes any remaining film and makes everything pop.
Then you put your outlet back in, and you’re done deal.
Common Mistakes I See (And How to Avoid Them)
Mixing too much grout at once
Prism is rapid setting. If you mix a giant batch, it can set up before you’re ready. Work smaller.
Using too much water on the first wipe
First wipe is shaping. Wring the sponge out hard. Too much water washes joints and makes them inconsistent.
Spreading too big of an area before wiping
If grout sets up too far on you, there’s no going back. Stay on it and wipe on time.
Expecting perfect corners on the first pass
Don’t. Get them close, then come back during the second wipe stage when the grout is firmer.
Ignoring the bottom joint movement problem
That countertop to wall joint is a common crack spot. Grout looks better, but if movement is likely, use a color matched sanded caulk there.
FAQ Section
Q. What grout should I use for an irregular subway tile backsplash with 1/16 to 1/8 inch joints?
I’m using Custom Prism for joints that vary between 1/16 and 1/8 inch. It’s easy to find and it works well for this kind of backsplash.
Q. Should beginners use white grout with white tile?
Yes. If you’re learning, white grout with white tile hides imperfections and blends your goof ups instead of highlighting them. Gray grout tends to make every imperfection stand out more.
Q. Do I put water or powder in the bucket first?
Water first, then add powder. That’s how I do it, and it helps with mixing consistency.
Q. Do I need to let grout slack?
Yes. Let it slack for 5 minutes, then remix. That slake time gives the grout a little initial set and makes it work better when you apply it.
Q. How do I know when to start wiping grout?
Use the finger test. Touch the grout. If you can’t push it in anymore, it’s ready to wipe. Don’t wait so long that it sets up hard, because you can ruin the job.
Q. What angle should I hold the grout float?
I pack joints at a shallow angle around 20 to 22 degrees, then hold the float sharper around 45 degrees to pull excess grout off the tile face.
Q. Should I grout the joint where the countertop meets the backsplash?
That joint often cracks because it’s a transition point with movement. I usually grout it first because it looks better, but if you want to avoid callbacks, you can preemptively use a color matched sanded caulk there.
Q. How long should I wait between the first wipe and final wipe?
In my process, I do a first wipe to shape joints, then I wait about 10 minutes and do a final wipe to remove haze and touch up corners.
Q. When do I do the final buff?
After everything is shaped and clean, you can buff with microfiber towels a couple hours later or even the next day. No rush.
Final Thoughts
If you take anything from this, take this: grout is timing, and grout is cleanup discipline.
Pick a forgiving color if you’re learning. Mix it right. Let it slack. Work smaller sections if you’re using rapid setting grout. Use your float to do most of the heavy lifting so wiping is easy. Wring your sponge out. Shape first, perfect later. And don’t be surprised if the bottom joint wants to crack someday. That’s movement, not failure.
If you want to keep leveling up at tile, I’d love to have you in the Tile Coach Forum. And if you finish a backsplash like this, seriously, tell me about it. I love those success stories.
Now go grout that backsplash. If I can do it, you can too.